Our major objective is to contribute to a better understanding of the structure, mode of biosynthesis, and physiological function of complex, carbohydrate-containing proteins of eukaryotic cells. These glycoproteins constitute major components of cell membranes and, in many instances, they are synthesized and exported from cells to provide specific constituents of extracellular body fluids and to the amorphous matrix of connective tissue. It is becoming increasingly apparent that many physiological phenomena are related to the interactions of a cell with environment and that frequently glycoprotein constituents of the cell envelope structure play a primary role in regulating these interactions. We are attempting to define, in specific molecular terms, the biochemical processes that contribute to the biosynthesis of glycoproteins, their intercellular mobilization in the complex membrane structure and their secretion from the cell.